CODEWITHSUNDEEP
vb.netfunctionoopeventsraiseevent
DragonInCresent
DragonInCresent

Reputation: 75

sub functions vs event, what is the difference?

I went through events in Vb.net and i found they are really an amazing feature..but still confused about how to use them effectively.

The real doubt is that the functions and sub could be effective alternative for events. Whatever i do with events i can manage to do it via functions and methods. Wherever there is Raisevent, i can substitute it with a function or procesure. so then, what is the real benefit of events and in which cases i can use them instead of functions and procedures?

Upvotes: 1

Views: 1163

Answers (2)

DragonInCresent
DragonInCresent

Reputation: 75

thank you for clarification, I got the point. The point I Missed was that : event is fired in the same class, but execution is done in a different class.

I mean, when I define a class, I can put RaiseEvent somewhere to recognize something, but I correlate the event with a sub in a different class.

so, in such a class called Wallet I can put a statement like : 

    If Dollars > 5 Then
        RaiseEvent Above5()
    End If

and in such different class called AllWallet :

Dim WithEvents myWallet as new Wallet
Sub myWallet_Above5() Handles myWallet.Above5
    MsgBox("Dollars are more than 5")
End Sub

otherwise, I mean if events are fired in the same class they are defined in , the sub and functions can substitute events.

thanks to all

Upvotes: 0

Pikoh
Pikoh

Reputation: 7703

Let's see if you understand it with an example. You have the Button control. It defines a lot of events (Click,MouseDown,Keypress...). When you put a button in a Form, you decide there what are the events you want to manage. So in the form you can do something when a button is clicked, or not doing anything.

Imagine if this was done with regular methods. In that case, the button should have a reference to the form where the button is, and the form should have a Click method, is it using it or not.

The event driven programing makes very easy to define some Events to signal when something happens in a class, and is the class that creates the instance the one that decides if that event is relevant or not.

Upvotes: 2

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